This attack targets a race condition occurring when multiple processes access and manipulate the same resource concurrently and the outcome of the execution depends on the particular order in which the access takes place. The attacker can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance a race condition can occur while accessing a file, the attacker can trick the system by replacing the original file with his version and cause the system to read the malicious file.

Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. The typical example is the file access. The attacker can leverage a file access race condition by "running the race", meaning that he would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the attacker could do something such as replace the file and cause an escalation of privilege.

The remote host is affected by the vulnerability described in GLSA-201805-15 (beep: Local privilege escalation)
A race condition, if setuid, was discovered in beep.
Impact :
A local attacker could escalate privileges.
Workaround :
There is no known workaround at this time.

It was discovered that there was a local privilege escalation vulnerability in beep, an 'advanced PC speaker beeper'.
For Debian 7 'Wheezy', this issue has been fixed in beep version 1.3-3+deb7u1.
We recommend that you upgrade your beep packages.
NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.